


Invisible Air

by AmmySunGod



Category: Fate/stay night & Related Fandoms, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: BAMF Midoriya Izuku, BAMF Uraraka Ochako, Dabi is Todoroki Touya, F/F, F/M, Gen, M/M, Midoriya Izuku Has a Quirk, Multi, Shiozaki Ibara is in Class 1-A
Language: English
Status: In-Progress
Published: 2020-02-14
Updated: 2020-03-04
Packaged: 2021-02-19 15:07:55
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 4,507
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22712719
Author URL: https://archiveofourown.org/users/AmmySunGod/pseuds/AmmySunGod
Summary: Izuku was five when he went to the doctor to find out if he had a quirk... He was twelve when it finally awakened.
Relationships: Bakugou Katsuki/Kirishima Eijirou, Jirou Kyouka/Yaoyorozu Momo, Midoriya Izuku & Uraraka Ochako, Midoriya Izuku/Shiozaki Ibara, Midoriya Izuku/Uraraka Ochako, Todoroki Fuyumi/Usagiyama Rumi | Miruko
Comments: 16
Kudos: 142





	1. Chapter 1

**Notes for the Chapter:**

> This was originally intened to be the second fic I posted here but sometimes you just feel more inspiration to write for something new.
> 
> Disclaimer: There is a app on the mobile play stores for android and IPhone called called Fanfic Pocket Archive Library (Unofficial) that is making money illegally through ads and paid subscription by using AO3 content without site or author permission. This breaks copyright law. Its up to you to report it if you want, I can't make you.

Invisible Air

Chapter One

Izuku Midoriya was five when he went to the doctor to get his quirk diagnosis, unlike most who went at four (He didn't find out until a month after the visit that the Quirkologist his mother originally wanted to take him to had gone missing a week before the scheduled appointment). After hours of poking and prodding they came to the conclusion he did have a quirk, a **very** strong one at that, his quirk levels the strongest they had seen in over a decade. But they had also reached the conclusion that because of how strong his quirk was it was very likely that it wouldn't manifest itself until his body was strong enough to use it, and that attempting to forcefully awaken it could quite possibly kill him. They took the doctor's word for it and left the building, Izuku holding his mom's hand. 

Inko and her son were in deep thought on the way home and into the night, Izuku in happiness at having a quirk even if he couldn't use it yet, and Inko was having thoughts of pulling Izuku from school and homeschooling him. Inko wasn't a idiot, she knew exactly what happened to quirkless children in schools and the suicide rates. Even though her son did have a quirk, he couldn't prove it, and most kids wouldn't take someone at their word, not teachers and certainly not some random kid's mother.

Despite her fears, all the children accepted that Izuku had a quirk he couldn't use yet, even though he had said it could be years before it manifested. Even Kacchan, as he always called Katsuki Bakugou, who had turned pale when Izuku had told him the possible consequences of trying using his quirk early, had accepted it.

The years passed and while Izuku wasn't really bullied, he certainly didn't have any friends, which left him quiet and soft spoken. Izuku didn't blame anyone for not associating with him, not when he had searched online and found out that late bloomers typically had violent quirk awakenings. Katsuki, who he had stopped calling Kacchan slowly over time, had attempted to repair their strained friendship and had stayed by his side for a few years. But eventually, even with Izuku keeping him down to earth, the everpresent words of praise had gotten to Katsuki, which ended in him breaking off their friendship.

Izuku was twelve when his quirk finally manifested. He was on his way to orientation for the first day of Aldera Junior High when he felt it, the telltale tingling that his doctor had said could happen. He immediately turned around and started running home, his phone already out and calling his mom. "Mom!" he yelled out as soon as she picked up. "It's finally happening!" he continued running towards their home as fast as he could. He could hear the happiness hidden in the sudden panic of her voice before she hung up and dialed the number the doctor had given her for when his quirk finally awoke.

When he finally reached the small one story house they lived in about 15 minutes later, there was already a truck there waiting to transport him and his mother to a reinforced training facility outside city limits. He hopped right into the back of the truck at the wave of the woman sitting there, and his mother who had been waiting at the passenger side door hopped in as well. The truck immediately pulled away and started speeding towards the facility as fast as the truck could go, knowing no one would stop them.

"Izuku Midoriya right!" the woman shouted over the rushing air. 

"Yeah!" he shouted back.

"My name is Minami, and I will be helping guide you in holding in the urge to let your quirk loose, if that happens before we reach the facility! Do you understand!" 

"Yes Ma'am!" he shouted with seriousness clear in his voice.

"Good! We will arrive at the facility in twenty minutes! If your quirk starts to act up, you tell me immediately!" 

"Understood Ma'am!"

Despite the high chance of it happening Izuku's quirk didn't act up on the way to the training facility. He was guided into a wide open room that was made of interlocking metal plates and sealed inside alone, while his mother was guided to a observation room.

"Okay Midoriya." Minami's voice came through an intercom he couldn't spot. "The room we put you in has been made specifically for people with incredibly destructive quirks. A prime example of this being the Pro Hero Endeavor, who had to spand a year here training almost daily to control his quirk to a level that was deemed acceptable for moving around in populated areas. Keep in mind your quirk levels right now are much higher than his were when he entered this facility." 

Izuku immediately understood what was left unsaid, he wasn't likely to leave the building anytime soon. But that was okay, he and his mother knew that this was going to happen, having been sent a packet explaining the training facility and what it entailed for late bloomers like him and those who couldn't control their overly destructive quirks. It was the reason he and his mother had moved to the small house they lived in. It was fifteen minutes away from the training facility and was already half paid for by the government, as the previous prime minister had implemented several laws for the welfare of late bloomers (It was a open secret that the former Japanese prime minister was sympathetic towards late bloomers, his own sister and her daughter being ones).

"The cameras are rolling and the sensors are active, so don't hesitate when the urge hits Midoriya."

One minute passed, then another, and another. It was at the thirteen minute mark when it happened. Izuku's whole body stiffened and his eyes widened. Everyone in the observation room immediately focused on the monitors. Izuku's whole body flickered in and out of existence before, to the complete shock of everyone in the observation room, the entirety of the reinforced room, with the exception of where he was standing, was suddenly covered in nicks and pockmarks with no clue as to how they happened. Minami and Inko turned to one of the currently gaping technicians in an attempt to figure out what happened.

"It... It was wind... wind that was completely invisible to the naked eye, and it also hid him from the cameras when it was active!" one the technicians exclaimed in excitement. This kind of quirk was something almost completely foreign to them, they had expected a super powered telekinetic or fire quirk, not a mutation. The murmurs of excitement died down when they heard a thud and saw that Izuku had passed out. They were about to send someone to bring him to the infirmary when Minami stopped them and motioned for one of the technicians to zoom in on Izuku's prone form. It became clear why when they saw his parts of his body disappear briefly before reappearing.

"Activate one of those one pointer robots that the Principal of UA was kind enough to send to us please." Minami told the technician, who started rapidly typing away. A portion of the wall slide away revealing the robot in question which instantly began to move towards Izuku's prone form, the technician guiding it's movements as it came to a stop in front of Izuku and its arm slowly lowered towards him. It made contact and nothing happened as the invisible wind flowed gently around the thick metal arm, seemingly sentient in the way it avoided the mechanical being.

Minami, Inko and the rest of the observation team breathed a sigh of relief at the lack of damage to the robot as the technician made the robot pick Izuku up and carry him to the infirmary where his body would be checked for any injuries and the beginning of any changes made to his body to make his quirk easier for him to use, as well as any sign of the drawback of his quirk if there is one. 

**Notes for the Chapter:**

> I intend for late bloomers to be more common then they are depicted in the original story, because it honestly makes more sense with the strong and versatile quirks in the manga and anime.  
> I forgot to add this originally but if you want to meet and sometimes chat with authors and other readers join this discord server.  
> [Epsi's Hoard](https://discord.gg/R2xBMFy)  
> Epsi is Epsilon the author of Total Command.


	2. Discussions and the days to come

**Summary for the Chapter:**

> Into talks to Minami, and Izuku wakes up and learns what's going to happen next

Invisible Air 

Chapter 2

After passing out from the violent awakening of his quirk and his transfer to the infirmary, Minami took the opportunity to talk to Inko. "So Mrs. Midoriya, what are your thoughts on your son's quirk? Has anything like it appeared in either your or your husbands ancestry?" Inko thought about it for a moment before giving her reply. "Not that I know of, but Hisashi never talked about his family so there could be someone on his side of the family." Minami took a moment to consider this before asking "How long would it take you to contact your husband? We can just pull his family medical records, but you can get more information from a person then a short summary of what their quirk does."

Inko sighed before speaking. "I'm going to be honest with you. I haven't spoken with Hisashi in years, not for a lack of trying. The checks he sends for our welfare are still coming so I know he is still alive. And no paperwork for divorce has been sent for me to sign." She knew logically that something was wrong, but she just couldn't bring herself to end that last connection she had with the man that she had loved for so many years. 

"Thank you anyways Mrs.Midoriya. Now, onto the matter of your son and his stay here at the Facility for and Around Training Deviants, F.A.T.D. for short." Minani said, confusing Inko.

"What does the deviant part of the name mean?" Inko questioned.

"Ah that, it is a common question so don't feel bad. Deviant refers to people whose quirk defies the norm, be it by being extremely powerful, having incredible versatility, or by simply having more than one quirk. It also refers to people whose quirk undergoes a evolution, which can mean many things, it could simply just become a much stronger version of the base quirk, it could be that they gained more abilities that relate to the base quirk, or they could mutate a completely different quirk from the original!" Minami gushed. "It's very exciting to work with Deviant class quirks.'' She recomposed herself.

"So my son has a deviant class quirk?"

"Oh very much so, what his quirk does is almost impossible you see. Most air based quirks leave visible evidence of being used, but with your son however, that doesn't seem to be the case. His quirk controls the air around but, it also makes that air completely invisible, which defies everything we know about air based quirks. Not even mentioning the fact the air coating him turned him invisible as well, which also breaks a few rules we have seen common in invisibility quirks."

"What does that mean for my son?"

"Honestly?" Minami sighed. "It could change everything. Or it could change nothing at all. It really all depends on how quickly he learns how to use his quirk and all the ins and out it has. He could be here for a few months, or a few years. We can only learn about it as fast as he can, as well as make some theories about what it can do, but that's it. Everything here depends on your son." 

"I guess that's all the questions I have for now. How long do you think it'll be before Izuku wakes up?" Inko knew that it wasn't going to be today, but she wanted to hope regardless.

"Given the strength of his quirk and the fact that it's awakening knocked him unconscious? It'll likely be a few days, a week at the most. He far surpassed our expectations of its strength. Considering that was the most durable room in the entire facility, the fact that his quirk was even able to damage the walls was astounding. Even more so if you consider that not one person before him has managed even a scratch on it during their awakenings, let alone the amount of damage Izuku did, and some not even once during their time here." Minami told her, her voice showing how impressed she was with her son and his quirk. "Now Mrs.Midoriya, I suggest that you go home and get some rest after today's excitement. Okay? And don't worry we will call you the moment your son wakes up and you will be able to come see him once we can determine if his quirk has any severe drawbacks."

Inko quickly thanked Minami for her kindness and let herself be escorted out of the facility and driven home by a member of their security personnel. When they got back to her small house, she gave the the security officer a quick bow of thanks before heading inside, already preparing for the eventual call that would tell her that her son had woken up and was ready to receive visitors.

Five Days Later

Izuku opened his eyes to a blurry a white ceiling. He blinked rapidly to bring the world into focus, and his attempt to move made him notice that his entire body was sore, as if he had just finished a intense workout that his body wasn't ready for. He looked around and saw no one was in the room with him he examined his surroundings. He was in what looked like a hospital room. ' _Why am I in a... oh that's right_.' memories of his quirk awakening and the rush of power flooded his mind. "I must have fallen unconscious" Izuku whispered to himself, and finally looked down at his body. He noticed that he was much skinnier than before, but had much better muscle definition. Next he took a look at the various tubes attached to his body, his eyes following each of them. Noticing that three of the six he saw were giving him nutrients. He finally noticed a note next to a button and slowly moved his arm to pick it up.

It read: ' _when you wake up and find this note press the button that you see next to it. it will notify us that you are awake so we can talk to you._ ' 

He put the note down and pressed the button, letting them know that he was awake. He waited and about twenty minutes later a man walked in with Minami, both looking at him with seriousness.

"Mr.Midoriya." the man spoke first "I am Dr.Hitsugi and I am the one assigned to watch over you while you are here. I'm sure by now you've noticed the visible changes in your body right? The sudden loss of fat and increased musculature?" Izuku nodded. "And I know you are smart enough to notice the large amount of nutrients currently being fed into your body right?" Izuku nodded again. "Good because that leads to the first subject I have to talk about. You see quirk mutations, or those that aren't related in any way to it's holders ancestry, are rather rare and even more dangerous to the person that has them. Because of the drastic difference in physiological needs the body can't start adapting to them until they are first used. Some start adapting slowly and others try to do it all at once. Are you following me here?" Izuku nodded slowly in slight confusion before it hit him. At the widening of his eyes the doctor continued. "As you probably just realized. Your body is currently playing catch up, and is burning any fuel it can use to bring your body up to snuff. We are estimating that it should take around two weeks to a month for it to stop provided you have the proper fuel. So for the next two weeks to a month you will be spending most of your time eating high calorie meals and drinking nutrient shakes. As well as doing minor physical exercises to keep up with the rapid changes in your body. Though it will only be nutrient shakes for the first few days, since you haven't actually eaten in five days we need to let your stomach get used to having food in it again."

"Okay doctor." Izuku said in a voice slightly raspy from a parched throat. "May I have some water now?" Izuku's question caused the man to blush in embarrassment

"Sorry Midoriya I'll be right back with some. In the meantime, Minami has some things to discuss with you as well pertaining to your stay here." The doctor spoke as he left the room.

"So Izuku, as I'm sure you know, here at F.A.T.D. we don't allow those undergoing training for destructive quirks to leave until they can control their quirks at a level that won't accidentally harm the populous." Izuku kept silent knowing that if he left without some form of control training his quirk could accidentally activate if stressed and hurt a lot of people. "Now after your body is finally ready you are going to be undergoing rigorous control training, and if you want to stay longer, and take some time to strengthen your quirk. But that decision belongs to you."

Izuku knew what he was offered was a amazing deal but "I don't think I can give you an answer on the quirk strength training right now, as I have no idea how much work I'm going to have to put into controlling my quirk in the first place." He did think it was strange that she offered it right now, but he had no idea what the exact standard procedure was for this place. Izuku suddenly realised that "This is a test, isn't it?" Izuku accused.

Minami smiled at him and said. "Yes, it is. Most people who come here don't figure that out until around the sixth question. You're the only one I've seen so far that figured it out on the first question. But the fact that you can recognise that it's a test is the real test. I'm not going to lie to you. There are going to a lot of these types of tests in store for you during your stay. So always stay on your toes Izuku." Her smile had turned back to seriousness by the end.

Izuku and Minami got to organizing his training schedule for when he finally could do it, so that he didn't fall behind on schoolwork while training. Minami actively encouraged to try and graduate from Junior High early, even going so far as to offer help in studying while he was on bed rest. Though Izuku suspected that was because he was who she had been assigned to, and an attempt to stave of the inevitable boredom that would come during the month that he couldn't really do anything during that time besides minor physical training and his eating.

Dr.Hitsugi had finally returned with water at this point, apologizing for taking so long. Izuku thanked him and sipped from the bottled water given to him, while the doctor told him the basics of the diet he would need to eat for the next few weeks, hanging off every detail and memorizing the times to eat.

When they finally left after the full outlining of his schedule Izuku finally let himself smile. 'things are looking up' he thought as he settled in for a long wait before a nurse brought his first 'meal'.

**Notes for the Chapter:**

> If you want to come chat with me and other authors feel free to join me here at the following discord link
> 
> [Epsi's Hoard](https://discord.gg/R2xBMFy)  
> 


	3. Testing and The Drawback

**Summary for the Chapter:**

> Izuku is up and about after a month and finally ready to give his quirk another go.

**Notes for the Chapter:**

> If you want to come chat with me and other authors feel free to join me here at the following discord link
> 
> [Epsi's Hoard](https://discord.gg/R2xBMFy)  
> 

Chapter 3

As Dr.Hitsugi had predicted the changes took almost a month to stop. The month that followed was hard on Izuku, mentally and physically. His mornings filled with a soreness that never seemed to stop from the rapid change his body was undergoing, to the afternoon spent exercising to adapt to those changes and studying to keep up his studies and possibly graduate early. All while eating meals high in calories and drinking specialised nutrient shakes. When his body finally stopped changing to adapt to his he found that during that time his height shot up from the short 4'4 that he was to a slightly taller than average 5' by the time the growth spurt stopped. His entire skeletal structure grew denser, and while it wasn't by much, he did gain some muscle. It was a week after the changes finished that Izuku was allowed to use his quirk again. Izuku stood in the room that they had brought him to when he first used his quirk. The room looked pristine, as if it didn't go through the abuse his quirk dished out. Izuku opened his mouth to ask about it, but realised it was a stupid question and cut it off before it started.

"Alright Izuku" Minami's voice came from the intercom, making Izuku jump slightly. "I want you to get a good feeling for your quirk. After you feel that you have a good handle on it, I want you to use it at the absolute lowest intensity you can. From there you should slowly work your way up your highest intensity if you can. As long as you remember to stop before you pass out it's fine. I would like you to be awake to describe it for me. Do you understand this?"

Izuku called out his confirmation with a loud 'Yes'. Izuku closed his eyes and began to concentrate on feeling out his quirk, the invisible 'muscle' that it exists as flexing a bit in response to his internal searching.  _ 'It feels a bit strange' _ Izuku thought  _ 'like it's tightly compressed, but also running free at the same time. The compressed feeling doesn't feel right to me though, as if it's not supposed to be like that' _ . With that thought in mind Izuku opened his eyes and slowly uncompressed his quirk, his hair and clothes moving in response to the sudden air movement small sections of his body disappearing and reappearing with distortions unnoticeable to the human eye, the amount of movement and size of disappearance growing as Izuku uncompressed his quirk more and more. The air in the room slowly but surely showing signs of Izuku's quirk at work. Izuku closed his eyes again to concentrate on keeping the rate of decompression slow, his quirk's increasing strength making it harder to keep a stable hold on. 

_ In the Observation Room _

Minami and the tech crew watched as the invisible winds picked up in their intensity, special sensors installed in the room based on the original data on Izuku's quirk sending a constant stream of data to the monitors. Their eyes went wide as Izuku went past the level of force that he showed during his quirks awakening. Jaws started to drop as Izuku showed no sign of stopping. With the wind speed in the room increasing beyond the estimated levels Minami made to use the intercom to tell Izuku to stop, when a burst of pressure and the sound of metal tearing coming from the speakers filled the observation room. Screams of surprise filled the room as they watched part of the heavily reinforced steel wall being torn apart under the gale force wind that Izuku was producing before it suddenly cut off. The few cameras that survived showed Izuku turn and look around the room in shock.

_ Back with Izuku - Same Time _

Sweat built on Izuku's forehead as the task of staying in control and keeping his quirk active was slowly but surely becoming insurmountable. The sweat being taken by the unseeable wind. Izuku was about to give up and reel his quirk in as best he could when he felt the last of the compression fade accompanied by the sound of shearing metal, which caused Izuku's concentration to snap and he felt his quirk to recompress itself. His eyes snapped open to devastation. The large room had enormous holes in the walls, some looking far to clean to be tears and others looking as if a large beast had dragged its claws across the wall. 

He was about to call out to them to open the door so he could leave when he felt something bubble up from his lungs. Unable to stop himself to stop himself he coughed violently into his hand. Pulling his hand back he stared down in shock at the red liquid that he coughed up. He coughed even more violently as he became aware of the pain in his chest, gripping his chest and collapsing as coughing fits racked his body, more blood shooting out of his mouth with each cough. He heard cries of shock and calls for the emergency medical team, and people begin to flood the room, Izuku's body being loaded onto a stretcher and Doctors with diagnostic quirks taking his vitals and figuring out where the damage is at. Izuku's consciousness fading as the pain grew harder to deal with, cries for him to stay awake falling on almost deaf ears as he struggled, almost choking on the blood he was coughing up. The last thing Izuku caught was a frantic shout of "It's his lungs!" and a glow started to surround his body before he passed out from the pain.

_ Back in the Observation Room _

Minami looked at the destruction Izuku's quirk had caused in the _seconds_ that it had been active at what she couldn't even be certain was full blast. "That... That's impossible..." Her whisper of shocked awe went completely unnoticed in the room that had already been vacated of every person but her. She stood up and started walking towards her office, using the time she took to get there to prepare herself for an angry/worried mother. As she dialed the number for Izuku's mother she sighed, and as she put the phone to her ear she said to herself, "I really hate this part of my job...".

  
  


Subject Name- Izuku Midoriya

Quirk- Invisible Air

Type-Emitter

Allows Izuku to create and manipulate a current of air invisible to the naked eye.

Notes- Eye based quirks may be able to see the near invisible distortions caused by the air moving.

Drawback- Overuse and/or Over-Exertion will damage Izuku's lungs. Can cause death.

Notes on drawback- Severity depends on length of overuse, or the strength of over-exertion.

Subject Name- Minami Shiozaki

Quirk- Absorption and Reflection

Type- Barrier

Allow Minami to create barriers that absorb and/or reflect attacks and force directed at it. Minami can also shoot out the absorbed attacks at the attacker.

Notes- If the barrier passes capacity it automatically releases stored energy instead of shattering

Drawback- If used to protect as a trap, whatever shape as long as it is a closed barrier, the barrier reaches capacity much quicker, this usually ends the lives of those trapped within.

Notes on drawback- Minami has used the drawback to great effect in stopping and ending the lives of out of control quirk holders, though she hates it and prays for the life of every single person she ends.

**Notes for the Chapter:**

> The problem Izuku had this chapter was that he started to hyperfocus, which made him ignore the growing stress in body and pain from his lungs. 
> 
> Also, I am not a professional writer. I'm a amateur at best but I'm working hard to get there. Writing is fun for me. And I really enjoy it.


End file.
